IEC 60282-1:2020 pdf free download – High-voltage fuses
5.3.5.3 Maximum arcing withstand time
The arcing withstand time is the time between the beginning of the arcing and the occurrenceof external damage to the fuse.The fuse manufacturer shall provide information regarding themaximum arcing withstand time, at a current value between 70 % and 100 % of ratedminimum breaking current.
This time shall be at least 0,1 s.The testing procedure is described in 8.3.3.3.
5.3.6 Allowable continuous current of a fuse-link (a)
The current assigned to a fuse-link that a new clean fuse-link will carry continuously, at aspecified surrounding temperature，without exceeding specified maximum temperatures whenmounted as specified by the manufacturer. The surrounding temperature may exceed 40 °C(see lEC TR 62655:2013).
NOTE lt is possible for allowable continuous current values to be higher than，equal to,or lower than theassigned rated current (7,). For example,higher values of allowable continuous current are primarily associatedwith certain fuse designs，while the more usual situation of lower values of allowable continuous current arenormally associated with elevated surrounding temperatures andlor specific application conditions. lt is alsopossible for a particular fuse-link to have several allowable continuous currents specified (e.g. each at a differentsurrounding temperature) or to have allowable continuous current defined by a formula ‘related to surroundingtemperature.
5.3.7 Maximum enclosure current(rfep)
The current assigned to a fuse-link by the FEP manufacturer that a new clean fuse-link willcarry continuously, at a specified surrounding temperature above 40 °℃,when mounted asspecified by the manufacturer and immersed in liquid.A fuse-link will have multiple values oflfep depending on the enclosure and surrounding temperature.(See IEC/TR 62655:2013.)Themaximum values of temperature given in Table 6 may be exceeded,but only by agreementbetween the manufacturer and user. The maximum enclosure current is used for the liquidtightness test (8.3.4).
7.6.1.6.1Fuses intended for use in air
For Test Duties 1 and 2, the conductors shall be arranged as shown in Figure 6, in order toreproduce the electromagnetic forces that may occur in service.To prevent any movement ofthe conductors from causing excessive mechanical stresses on the fuse-base, the conductorsshall be secured at a distance equal to the insulator height if this height exceeds 0,50 m(20 in), or at 0,50 m (20 in) if the insulator height does not exceed 0,50 m (20 in).The bendsshall be placed immediately after the bracing points. No arrangements are specified for TestDuty 3. The fuse shall be tested in the vertical orientation unless it is known that thehorizontal arrangement is more severe, in which case the fuse shall be tested horizontally. lfa fuse-link is not usually mounted in a fuse base, the mounting and orientation shall be asspecified by the manufacturer.
7.6.1.6.2Fuses intended for use in liquid-filled enclosures
Test Duties 1,2,3, and I, may be performed in air or in a liquid-filled enclosure.Since testingin air is held to be more onerous，this may only be done with the agreement of the fusemanufacturer,and in the case of failure, the relevant test duty may be repeated with the fusein a liquid-filled enclosure，using an arrangement of test conductors suitable for thatenclosure. The liquid-filled enclosure may be the same as used for the temperature rise tests,suitably reinforced, where necessary, with the fuse-link moved to equalise dielectric clearanceto the tank and utilising suitable fuse contacts.